fix(timeline): update responses after a successful decryption

Fixes #4196.

crates/matrix-sdk-ui/src/timeline/event_handler.rs

@@ -1190,8 +1190,34 @@ impl<'a, 'o> TimelineEventHandler<'a, 'o> {
                 }
             }
 
-            Flow::Remote { position: TimelineItemPosition::Update(idx), .. } => {
+            Flow::Remote {
+                event_id: decrypted_event_id,
+                position: TimelineItemPosition::Update(idx),
+                ..
+            } => {
                 trace!("Updating timeline item at position {idx}");
+
+                // Update all events that replied to this previously encrypted message.
+                self.items.for_each(|mut entry| {
+                    let Some(event_item) = entry.as_event() else { return };
+                    let Some(message) = event_item.content.as_message() else { return };
+                    let Some(in_reply_to) = message.in_reply_to() else { return };
+                    if *decrypted_event_id == in_reply_to.event_id {
+                        trace!(reply_event_id = ?event_item.identifier(), "Updating response to edited event");
+                        let in_reply_to = InReplyToDetails {
+                            event_id: in_reply_to.event_id.clone(),
+                            event: TimelineDetails::Ready(Box::new(
+                                RepliedToEvent::from_timeline_item(&item),
+                            )),
+                        };
+                        let new_reply_content =
+                            TimelineItemContent::Message(message.with_in_reply_to(in_reply_to));
+                        let new_reply_item =
+                            entry.with_kind(event_item.with_content(new_reply_content, None));
+                        ObservableVectorTransactionEntry::set(&mut entry, new_reply_item);
+                    }
+                });
+
                 let internal_id = self.items[*idx].internal_id.clone();
                 self.items.set(*idx, TimelineItem::new(item, internal_id));
             }

crates/matrix-sdk-ui/src/timeline/tests/encryption.rs

@@ -20,17 +20,19 @@ use std::{
     sync::{Arc, Mutex},
 };
 
+use as_variant::as_variant;
 use assert_matches::assert_matches;
 use assert_matches2::assert_let;
 use eyeball_im::VectorDiff;
 use matrix_sdk::{
+    assert_next_matches_with_timeout,
     crypto::{decrypt_room_key_export, types::events::UtdCause, OlmMachine},
     test_utils::test_client_builder,
 };
 use matrix_sdk_base::deserialized_responses::{SyncTimelineEvent, UnableToDecryptReason};
-use matrix_sdk_test::{async_test, BOB};
+use matrix_sdk_test::{async_test, ALICE, BOB};
 use ruma::{
-    assign,
+    assign, event_id,
     events::room::encrypted::{
         EncryptedEventScheme, MegolmV1AesSha2ContentInit, Relation, Replacement,
         RoomEncryptedEventContent,
@@ -44,7 +46,7 @@ use stream_assert::assert_next_matches;
 
 use super::TestTimeline;
 use crate::{
-    timeline::{EncryptedMessage, TimelineItemContent},
+    timeline::{EncryptedMessage, TimelineDetails, TimelineItemContent},
     unable_to_decrypt_hook::{UnableToDecryptHook, UnableToDecryptInfo, UtdHookManager},
 };
 
@@ -557,6 +559,128 @@ async fn test_utd_cause_for_missing_membership_is_unknown() {
     assert_eq!(*cause, UtdCause::Unknown);
 }
 
+#[async_test]
+async fn test_retry_decryption_updates_response() {
+    const SESSION_ID: &str = "gM8i47Xhu0q52xLfgUXzanCMpLinoyVyH7R58cBuVBU";
+    const SESSION_KEY: &[u8] = b"\
+        -----BEGIN MEGOLM SESSION DATA-----\n\
+        ASKcWoiAVUM97482UAi83Avce62hSLce7i5JhsqoF6xeAAAACqt2Cg3nyJPRWTTMXxXH7TXnkfdlmBXbQtq5\
+        bpHo3LRijcq2Gc6TXilESCmJN14pIsfKRJrWjZ0squ/XsoTFytuVLWwkNaW3QF6obeg2IoVtJXLMPdw3b2vO\
+        vgwGY3OMP0XafH13j1vcb6YLzvgLkZQLnYvd47hv3yK/9GmKS9tokuaQ7dCVYckYcIOS09EDTs70YdxUd5WG\
+        rQynATCLFP1p/NAGv70r9MK7Cy/mNpjD0r4qC7UEDIoi1kOWzHgnLo19wtvwsb8Fg8ATxcs3Wmtj8hIUYpDx\
+        ia4sM10zbytUuaPUAfCDf42IyxdmOnGe1CueXhgI71y+RW0s0argNqUt7jB70JT0o9CyX6UBGRaqLk2MPY9T\
+        hUu5J8X3UgIa6rcbWigzohzWm9rdbEHFrSWqjpfQYMaAKQQgETrjSy4XTrp2RhC2oNqG/hylI4ab+F4X6fpH\
+        DYP1NqNMP5g36xNu7LhDnrUB5qsPjYOmWORxGLfudpF3oLYCSlr3DgHqEIB6HjQblLZ3KQuPBse3zxyROTnS\
+        AhdPH4a/z1wioFtKNVph3hecsiKEdqnz4Y2coSIdhz58mJ9JWNQoFAENE5CSsoEZAGvafYZVpW4C75YY2zq1\
+        wIeiFi1dT43/jLAUGkslsi1VvnyfUu8qO404RxYO3XHoGLMFoFLOO+lZ+VGci2Vz10AhxJhEBHxRKxw4k2uB\
+        HztoSJUr/2Y\n\
+        -----END MEGOLM SESSION DATA-----";
+
+    let timeline = TestTimeline::new();
+    let mut stream = timeline.subscribe_events().await;
+
+    let original_event_id = event_id!("$original");
+    let f = &timeline.factory;
+    timeline
+        .handle_live_event(
+            f.event(RoomEncryptedEventContent::new(
+                EncryptedEventScheme::MegolmV1AesSha2(
+                    MegolmV1AesSha2ContentInit {
+                        ciphertext: "\
+                            AwgAEtABPRMavuZMDJrPo6pGQP4qVmpcuapuXtzKXJyi3YpEsjSWdzuRKIgJzD4P\
+                            cSqJM1A8kzxecTQNJsC5q22+KSFEPxPnI4ltpm7GFowSoPSW9+bFdnlfUzEP1jPq\
+                            YevHAsMJp2fRKkzQQbPordrUk1gNqEpGl4BYFeRqKl9GPdKFwy45huvQCLNNueql\
+                            CFZVoYMuhxrfyMiJJAVNTofkr2um2mKjDTlajHtr39pTG8k0eOjSXkLOSdZvNOMz\
+                            hGhSaFNeERSA2G2YbeknOvU7MvjiO0AKuxaAe1CaVhAI14FCgzrJ8g0y5nly+n7x\
+                            QzL2G2Dn8EoXM5Iqj8W99iokQoVsSrUEnaQ1WnSIfewvDDt4LCaD/w7PGETMCQ"
+                            .to_owned(),
+                        sender_key: "DeHIg4gwhClxzFYcmNntPNF9YtsdZbmMy8+3kzCMXHA".to_owned(),
+                        device_id: "NLAZCWIOCO".into(),
+                        session_id: SESSION_ID.into(),
+                    }
+                    .into(),
+                ),
+                None,
+            ))
+            .event_id(original_event_id)
+            .sender(&BOB)
+            .into_utd_sync_timeline_event(),
+        )
+        .await;
+
+    timeline
+        .handle_live_event(f.text_msg("well said!").reply_to(original_event_id).sender(&ALICE))
+        .await;
+
+    // We receive the UTD.
+    {
+        let event = assert_next_matches!(stream, VectorDiff::PushBack { value } => value);
+        assert_let!(
+            TimelineItemContent::UnableToDecrypt(EncryptedMessage::MegolmV1AesSha2 {
+                session_id,
+                ..
+            }) = event.content()
+        );
+        assert_eq!(session_id, SESSION_ID);
+    }
+
+    // We receive the text response.
+    {
+        let event = assert_next_matches!(stream, VectorDiff::PushBack { value } => value);
+        let msg = event.content().as_message().unwrap();
+        assert_eq!(msg.body(), "well said!");
+
+        let reply_details = msg.in_reply_to().unwrap();
+        assert_eq!(reply_details.event_id, original_event_id);
+
+        let replied_to = as_variant!(&reply_details.event, TimelineDetails::Ready).unwrap();
+        assert!(replied_to.content.as_unable_to_decrypt().is_some());
+    }
+
+    // Import a room key backup.
+    let own_user_id = user_id!("@example:morheus.localhost");
+    let exported_keys = decrypt_room_key_export(Cursor::new(SESSION_KEY), "1234").unwrap();
+
+    let olm_machine = OlmMachine::new(own_user_id, "SomeDeviceId".into()).await;
+    olm_machine.store().import_exported_room_keys(exported_keys, |_, _| {}).await.unwrap();
+
+    // Retry decrypting the UTD.
+    timeline
+        .controller
+        .retry_event_decryption_test(
+            room_id!("!DovneieKSTkdHKpIXy:morpheus.localhost"),
+            olm_machine,
+            Some(iter::once(SESSION_ID.to_owned()).collect()),
+        )
+        .await;
+
+    // The response is updated.
+    {
+        let event = assert_next_matches_with_timeout!(
+            stream,
+            VectorDiff::Set { index: 1, value } => value
+        );
+
+        let msg = event.content().as_message().unwrap();
+        assert_eq!(msg.body(), "well said!");
+
+        let reply_details = msg.in_reply_to().unwrap();
+        assert_eq!(reply_details.event_id, original_event_id);
+
+        let replied_to = as_variant!(&reply_details.event, TimelineDetails::Ready).unwrap();
+        assert_eq!(replied_to.content.as_message().unwrap().body(), "It's a secret to everybody");
+    }
+
+    // The event itself is decrypted.
+    {
+        let event = assert_next_matches!(stream, VectorDiff::Set { index: 0, value } => value);
+        assert_matches!(event.encryption_info(), Some(_));
+        assert_let!(TimelineItemContent::Message(message) = event.content());
+        assert_eq!(message.body(), "It's a secret to everybody");
+        assert!(!event.is_highlighted());
+    }
+}
+
 fn utd_event_with_unsigned(unsigned: serde_json::Value) -> SyncTimelineEvent {
     let raw = Raw::from_json(
         to_raw_value(&json!({